1 Select a procedure
Musculoskeletal & Pain
Oncology & Tumour Therapy
Women's Health
Vascular Health
Vascular Access & Intervention
Diagnostics
2 Planned anaesthesia / sedation
3 Patient factors (optional — tick any that apply)
4 Select the medication
Diabetes medications
Other regular medications
This is guideline-based general information only. Clinical judgement should always be used — please seek further advice from our rooms for any specific patient.
Not sure, or a borderline case?
Get in touch before the appointment
For complex medication combinations, reduced kidney function, or insulin-dependent patients, contact our rooms directly rather than guessing.
Contact our roomsQuick reference
General guidance by medication class. Individual patient factors and procedure type can change what applies — use the tool above for a case-specific starting point.
| Diabetes medication | General guidance |
|---|---|
| Metformin | Continue if eGFR ≥ 30 and no AKI and non-arterial procedure; otherwise withhold at time of procedure and for 48h after |
| Sulfonylureas | Withhold the dose while fasting; resume with the next meal |
| DPP-4 inhibitors | Continue as normal |
| Thiazolidinediones | Continue as normal |
| SGLT2 inhibitors | Withhold day of procedure (day-only); withhold 2–3 days before if overnight stay / bowel prep involved |
| GLP-1 agonists | Continue — manage via 24h clear fluid diet if sedation/GA planned |
| Insulin | Individualised — plan with the patient's diabetes team |
| Other regular medication | General guidance |
|---|---|
| Statins | Continue as normal |
| Beta-blockers / CCBs | Continue as normal |
| ACE inhibitors / ARBs | Continue for local/sedation; consider omitting morning dose for general anaesthetic |
| Diuretics | Sometimes withheld for practical reasons if fasting/sedation planned |
| Thyroid hormone | Continue as normal |
| Long-term corticosteroids | Continue — never stop abruptly; larger procedures may need dose adjustment |
Common questions
Should metformin be stopped before a scan or procedure?
For patients with normal kidney function (eGFR 30 or above) having a non-arterial procedure, metformin is continued as normal. It is withheld around the procedure, and for 48 hours afterward, if kidney function is reduced, there is acute kidney injury, or the procedure is an arterial catheter study.
Should GLP-1 medications like Ozempic be stopped before a procedure?
No — current guidance is to continue GLP-1 receptor agonists. If sedation or a general anaesthetic is planned, a 24-hour clear fluid diet the day before is used instead of stopping the medication.
Do blood pressure and cholesterol medications need to be stopped before a procedure?
Generally no. Statins, beta-blockers, calcium channel blockers and thyroid medication are continued as normal. ACE inhibitors and ARBs are usually continued, but may be omitted on the morning of a procedure involving a general anaesthetic.
This tool provides general, guideline-informed educational information for reception staff, referrers and patients, and does not constitute individualised medical advice for any specific patient. Clinical judgement should always be used, and further advice should be sought for any complex or borderline case — please contact our rooms or the patient's usual prescriber.
For anticoagulant and antiplatelet medications, see our separate periprocedural anticoagulation & antiplatelet guide. For a fuller explanation of the reasoning behind this guidance, see our periprocedural fasting & medications guide.
- Australian and New Zealand College of Anaesthetists (ANZCA) et al. Clinical Practice Recommendations: Periprocedural GLP-1RA Use. April 2025 (updated).
- Australian Diabetes Society (ADS) and ANZCA. ADS-ANZCA Perioperative Diabetes and Hyperglycaemia Guidelines (Adults). 2022.
- American College of Radiology (ACR). ACR Manual on Contrast Media — Metformin chapter. 2024–2025 editions.
- ANZCA PG07: Guideline on pre-anaesthesia consultation, Appendix 1 (fasting). 2024.